Brand new set of crankshaft bearings and seals. Fits Stihl chainsaw model MS660 and 066. Also fits the 064 if we substitute the correct seal for the flywheel side. If you are ordering these for an 064 please add a note to your purchase or send us a message so we can be sure to include the correct seals. If no note or message this set will ship with the seals for the 066/MS660.